Forgot to include this in 22f448b6

Cleanup

Review fixes

This just returns the size of the language code buffer.

The return code should be 32-bit in size.

string_util: Get rid of separate resize() in CPToUTF16(), UTF16ToUTF8(), CodeToUTF8() and UTF8ToUTF16()

There's no need to perform the resize separately here, since the
constructor allows presizing the buffer.

Also move the empty string check before the construction of the string
to make the early out more straightforward.

This is equivalent to doing:

push_back(std::string(""));

which is likely not to cause issues, assuming a decent std::string
implementation with small-string optimizations implemented in its
design, however it's still a little unnecessary to copy that buffer
regardless. Instead, we can use emplace_back() to directly construct the
empty string within the std::vector instance, eliminating any possible
overhead from the copy.

We can just use the variant of std::string's replace() function that can
replace an occurrence with N copies of the same character, eliminating
the need to allocate a std::string containing a buffer of spaces.

We don't need to toss away the Subroutine instance after the find() call
and reconstruct another instance with the same data right after it.
Particularly give Subroutine contains a std::set.

ReplaceFileWithSubdirectory() takes a VirtualFile and a VirtualDir, but
it was being passed a string as one of its arguments. The only reason
this never caused issues is because this template isn't instantiated
anywhere yet.

This corrects an issue before it occurs.

Avoids unnecessary construction of std::string instances where
applicable.

We can just leverage std::unique_ptr to automatically close these for us
in error cases instead of jumping to the end of the function to call
fclose on them.

This avoids a truncating cast on size. I doubt we'd ever traverse a
directory this large, however we also shouldn't truncate sizes away.

Avoids unnecessary copies when building up the FST entries.

This behaves quite similarly to the SubmitGPFIFO command. Referenced from Ryujinx.
Many thanks to @gdkchan for investigating this!

Instead of using an unsigned int as a parameter and expecting a user to
always pass in the correct values, we can just convert the enum into an
enum class and use that type as the parameter type instead, which makes
the interface more type safe.

We also get rid of the bookkeeping "NUM_" element in the enum by just
using an unordered map. This function is generally low-frequency in
terms of calls (and I'd hope so, considering otherwise would mean we're
slamming the disk with IO all the time) so I'd consider this acceptable
in this case.

Given both operands are the same type, there won't be an issue with
overload selection that requires making this explicit.

This is entirely unused in the codebase.

Given we're already constructing the error code, we don't need to call
the constructor inside of it.

We already return by value, so we don't explicitly need to make the
copy.

Avoids unnecessary atomic increment and decrement operations.

This is a little bit more self-documenting on what is being done here.

We can simply use std::clamp() here, instead of using an equivalent
with std::max() and std::min().

Given the data is intended to be directly written, there's no need to
take the std::vector by value and copy the data.

Provides the same behavior, but with less writing

vfs: Amend constness on pointers in WriteBytes() and WriteArrays() member functions to be const qualified

These functions don't modify the data being pointed to, so these can be
pointers to const data

Note that there's currently a dynarmic bug preventing this register from being written.